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Quantitative measurements of second harmonic Doppler using ultrasound contrast agents
- Source :
- Ultrasound in Medicine & Biology. 22:1205-1214
- Publication Year :
- 1996
- Publisher :
- Elsevier BV, 1996.
-
Abstract
- Quantitative measurements of second harmonic and first harmonic Doppler were carried out using two ultrasound contrast agents, Albunex ® and FS069. The RMS amplitudes of the Doppler shift spectra were measured as a function of the concentration of the agents, frequency and transmitted acoustic pressure. The results showed that, for a given lot of contrast agent investigated, FS069 was able to produce higher levels of first and, especially, second harmonic signals compared to Albunex. Under the same experimental conditions, the RMS Doppler amplitude (RDA) of FS069 was 3.8 ± 0.8 dB higher than Albunex at first harmonic and 12.6 ± 0.8 dB higher at second harmonic. The ratio of the second harmonic to first harmonic RDA, which we called R2R1, decreases at a rate of 7 dB/MHz for both agents with increasing frequency. The difference in the value of R2R1 between FS069 and Albunex at any frequency was approximately 4.5 dB. R2R1 was found to increase linearly as a function of the transmitted acoustic pressure for both agents. Simulations using the Rayleigh-Plesset equation show a decrease of R2R1 at a rate of 5 dB/MHz. Comparison of experimental results with theory indicates that the shell elasticity parameter may be an increasing function of the mean diameter of the bubbles.
- Subjects :
- Acoustics and Ultrasonics
Acoustics
Biophysics
Contrast Media
Spectral line
symbols.namesake
Optics
Albumins
Radiology, Nuclear Medicine and imaging
Elasticity (economics)
Sound pressure
Physics
Fluorocarbons
Radiological and Ultrasound Technology
business.industry
Ultrasound
Models, Cardiovascular
Ultrasonography, Doppler
Fundamental frequency
Image Enhancement
Microspheres
Amplitude
symbols
Harmonic
business
Doppler effect
Blood Flow Velocity
Subjects
Details
- ISSN :
- 03015629
- Volume :
- 22
- Database :
- OpenAIRE
- Journal :
- Ultrasound in Medicine & Biology
- Accession number :
- edsair.doi.dedup.....3e50221edc64a78cb66792c39d4092f6